cregit-Linux how code gets into the kernel

Release 4.11 net/rds/tcp_recv.c

Directory: net/rds
/*
 * Copyright (c) 2006 Oracle.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <net/tcp.h>

#include "rds.h"
#include "tcp.h"


static struct kmem_cache *rds_tcp_incoming_slab;


static void rds_tcp_inc_purge(struct rds_incoming *inc) { struct rds_tcp_incoming *tinc; tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); rdsdebug("purging tinc %p inc %p\n", tinc, inc); skb_queue_purge(&tinc->ti_skb_list); }

Contributors

PersonTokensPropCommitsCommitProp
Andy Grover45100.00%2100.00%
Total45100.00%2100.00%


void rds_tcp_inc_free(struct rds_incoming *inc) { struct rds_tcp_incoming *tinc; tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); rds_tcp_inc_purge(inc); rdsdebug("freeing tinc %p inc %p\n", tinc, inc); kmem_cache_free(rds_tcp_incoming_slab, tinc); }

Contributors

PersonTokensPropCommitsCommitProp
Andy Grover48100.00%1100.00%
Total48100.00%1100.00%

/* * this is pretty lame, but, whatever. */
int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to) { struct rds_tcp_incoming *tinc; struct sk_buff *skb; int ret = 0; if (!iov_iter_count(to)) goto out; tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); skb_queue_walk(&tinc->ti_skb_list, skb) { unsigned long to_copy, skb_off; for (skb_off = 0; skb_off < skb->len; skb_off += to_copy) { to_copy = iov_iter_count(to); to_copy = min(to_copy, skb->len - skb_off); if (skb_copy_datagram_iter(skb, skb_off, to, to_copy)) return -EFAULT; rds_stats_add(s_copy_to_user, to_copy); ret += to_copy; if (!iov_iter_count(to)) goto out; } } out: return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Andy Grover11778.52%266.67%
Al Viro3221.48%133.33%
Total149100.00%3100.00%

/* * We have a series of skbs that have fragmented pieces of the congestion * bitmap. They must add up to the exact size of the congestion bitmap. We * use the skb helpers to copy those into the pages that make up the in-memory * congestion bitmap for the remote address of this connection. We then tell * the congestion core that the bitmap has been changed so that it can wake up * sleepers. * * This is racing with sending paths which are using test_bit to see if the * bitmap indicates that their recipient is congested. */
static void rds_tcp_cong_recv(struct rds_connection *conn, struct rds_tcp_incoming *tinc) { struct sk_buff *skb; unsigned int to_copy, skb_off; unsigned int map_off; unsigned int map_page; struct rds_cong_map *map; int ret; /* catch completely corrupt packets */ if (be32_to_cpu(tinc->ti_inc.i_hdr.h_len) != RDS_CONG_MAP_BYTES) return; map_page = 0; map_off = 0; map = conn->c_fcong; skb_queue_walk(&tinc->ti_skb_list, skb) { skb_off = 0; while (skb_off < skb->len) { to_copy = min_t(unsigned int, PAGE_SIZE - map_off, skb->len - skb_off); BUG_ON(map_page >= RDS_CONG_MAP_PAGES); /* only returns 0 or -error */ ret = skb_copy_bits(skb, skb_off, (void *)map->m_page_addrs[map_page] + map_off, to_copy); BUG_ON(ret != 0); skb_off += to_copy; map_off += to_copy; if (map_off == PAGE_SIZE) { map_off = 0; map_page++; } } } rds_cong_map_updated(map, ~(u64) 0); }

Contributors

PersonTokensPropCommitsCommitProp
Andy Grover180100.00%1100.00%
Total180100.00%1100.00%

struct rds_tcp_desc_arg { struct rds_conn_path *conn_path; gfp_t gfp; };
static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb, unsigned int offset, size_t len) { struct rds_tcp_desc_arg *arg = desc->arg.data; struct rds_conn_path *cp = arg->conn_path; struct rds_tcp_connection *tc = cp->cp_transport_data; struct rds_tcp_incoming *tinc = tc->t_tinc; struct sk_buff *clone; size_t left = len, to_copy; rdsdebug("tcp data tc %p skb %p offset %u len %zu\n", tc, skb, offset, len); /* * tcp_read_sock() interprets partial progress as an indication to stop * processing. */ while (left) { if (!tinc) { tinc = kmem_cache_alloc(rds_tcp_incoming_slab, arg->gfp); if (!tinc) { desc->error = -ENOMEM; goto out; } tc->t_tinc = tinc; rdsdebug("alloced tinc %p\n", tinc); rds_inc_path_init(&tinc->ti_inc, cp, cp->cp_conn->c_faddr); tinc->ti_inc.i_rx_lat_trace[RDS_MSG_RX_HDR] = local_clock(); /* * XXX * we might be able to use the __ variants when * we've already serialized at a higher level. */ skb_queue_head_init(&tinc->ti_skb_list); } if (left && tc->t_tinc_hdr_rem) { to_copy = min(tc->t_tinc_hdr_rem, left); rdsdebug("copying %zu header from skb %p\n", to_copy, skb); skb_copy_bits(skb, offset, (char *)&tinc->ti_inc.i_hdr + sizeof(struct rds_header) - tc->t_tinc_hdr_rem, to_copy); tc->t_tinc_hdr_rem -= to_copy; left -= to_copy; offset += to_copy; if (tc->t_tinc_hdr_rem == 0) { /* could be 0 for a 0 len message */ tc->t_tinc_data_rem = be32_to_cpu(tinc->ti_inc.i_hdr.h_len); tinc->ti_inc.i_rx_lat_trace[RDS_MSG_RX_START] = local_clock(); } } if (left && tc->t_tinc_data_rem) { to_copy = min(tc->t_tinc_data_rem, left); clone = pskb_extract(skb, offset, to_copy, arg->gfp); if (!clone) { desc->error = -ENOMEM; goto out; } skb_queue_tail(&tinc->ti_skb_list, clone); rdsdebug("skb %p data %p len %d off %u to_copy %zu -> " "clone %p data %p len %d\n", skb, skb->data, skb->len, offset, to_copy, clone, clone->data, clone->len); tc->t_tinc_data_rem -= to_copy; left -= to_copy; offset += to_copy; } if (tc->t_tinc_hdr_rem == 0 && tc->t_tinc_data_rem == 0) { struct rds_connection *conn = cp->cp_conn; if (tinc->ti_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP) rds_tcp_cong_recv(conn, tinc); else rds_recv_incoming(conn, conn->c_faddr, conn->c_laddr, &tinc->ti_inc, arg->gfp); tc->t_tinc_hdr_rem = sizeof(struct rds_header); tc->t_tinc_data_rem = 0; tc->t_tinc = NULL; rds_inc_put(&tinc->ti_inc); tinc = NULL; } } out: rdsdebug("returning len %zu left %zu skb len %d rx queue depth %d\n", len, left, skb->len, skb_queue_len(&tc->t_sock->sk->sk_receive_queue)); return len - left; }

Contributors

PersonTokensPropCommitsCommitProp
Andy Grover46086.96%233.33%
Sowmini Varadhan458.51%350.00%
Santosh Shilimkar244.54%116.67%
Total529100.00%6100.00%

/* the caller has to hold the sock lock */
static int rds_tcp_read_sock(struct rds_conn_path *cp, gfp_t gfp) { struct rds_tcp_connection *tc = cp->cp_transport_data; struct socket *sock = tc->t_sock; read_descriptor_t desc; struct rds_tcp_desc_arg arg; /* It's like glib in the kernel! */ arg.conn_path = cp; arg.gfp = gfp; desc.arg.data = &arg; desc.error = 0; desc.count = 1; /* give more than one skb per call */ tcp_read_sock(sock->sk, &desc, rds_tcp_data_recv); rdsdebug("tcp_read_sock for tc %p gfp 0x%x returned %d\n", tc, gfp, desc.error); return desc.error; }

Contributors

PersonTokensPropCommitsCommitProp
Andy Grover9793.27%133.33%
Sowmini Varadhan65.77%133.33%
Stephen Hemminger10.96%133.33%
Total104100.00%3100.00%

/* * We hold the sock lock to serialize our rds_tcp_recv->tcp_read_sock from * data_ready. * * if we fail to allocate we're in trouble.. blindly wait some time before * trying again to see if the VM can free up something for us. */
int rds_tcp_recv_path(struct rds_conn_path *cp) { struct rds_tcp_connection *tc = cp->cp_transport_data; struct socket *sock = tc->t_sock; int ret = 0; rdsdebug("recv worker path [%d] tc %p sock %p\n", cp->cp_index, tc, sock); lock_sock(sock->sk); ret = rds_tcp_read_sock(cp, GFP_KERNEL); release_sock(sock->sk); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Andy Grover6286.11%150.00%
Sowmini Varadhan1013.89%150.00%
Total72100.00%2100.00%


void rds_tcp_data_ready(struct sock *sk) { void (*ready)(struct sock *sk); struct rds_conn_path *cp; struct rds_tcp_connection *tc; rdsdebug("data ready sk %p\n", sk); read_lock_bh(&sk->sk_callback_lock); cp = sk->sk_user_data; if (!cp) { /* check for teardown race */ ready = sk->sk_data_ready; goto out; } tc = cp->cp_transport_data; ready = tc->t_orig_data_ready; rds_tcp_stats_inc(s_tcp_data_ready_calls); if (rds_tcp_read_sock(cp, GFP_ATOMIC) == -ENOMEM) queue_delayed_work(rds_wq, &cp->cp_recv_w, 0); out: read_unlock_bh(&sk->sk_callback_lock); ready(sk); }

Contributors

PersonTokensPropCommitsCommitProp
Andy Grover11490.48%240.00%
Sowmini Varadhan97.14%120.00%
Eric Dumazet21.59%120.00%
David S. Miller10.79%120.00%
Total126100.00%5100.00%


int rds_tcp_recv_init(void) { rds_tcp_incoming_slab = kmem_cache_create("rds_tcp_incoming", sizeof(struct rds_tcp_incoming), 0, 0, NULL); if (!rds_tcp_incoming_slab) return -ENOMEM; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Andy Grover38100.00%2100.00%
Total38100.00%2100.00%


void rds_tcp_recv_exit(void) { kmem_cache_destroy(rds_tcp_incoming_slab); }

Contributors

PersonTokensPropCommitsCommitProp
Andy Grover12100.00%1100.00%
Total12100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Andy Grover120789.94%428.57%
Sowmini Varadhan725.37%428.57%
Al Viro322.38%17.14%
Santosh Shilimkar241.79%17.14%
Tejun Heo30.22%17.14%
Eric Dumazet20.15%17.14%
David S. Miller10.07%17.14%
Stephen Hemminger10.07%17.14%
Total1342100.00%14100.00%
Directory: net/rds
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.